Apparatus for temperature control



' A ril 3, 1.928. 1,664,965

1 A. BONDS APPARATUS FOR TEMPERATURE CONTROL Filed May 19. 1926 2sheets-Sheet 1 Qhwentor:

$5567 BOA/05, v

Aprifi 6, E928. 1,664,965

A. BONDS APPARATUS \FOR TEMPERATURE CONTROL Filed May 19. 1926 2Sheets-Sheet 2 fitnesses as applied to a Patented 3, 192 8.

ALBEBT BONDS, OF CLEVELAND, OHIO.

APPARATUS FOR TEMPERATURE CONTROL.

Application filed May 19, 1926. Serial No. 110,303.

This invention relates to apparatus for maintaining a constanttemperature at a predetermined point in a heated receptacle containinggaseous or liquid matter, molten metal and the like, and has for itsobject the provision of a sensitive control of the temperature, and theelimination of what is commonly called lag from the temperature control.7 p

The invention will be described in detail spelter bath for galvanizingWire, although itwill be understood that itsuse is in nowise limited tocontrolling the temperature of a spelter bath since it may be used tocontrol the temperature of many other objects.

In the drawings:

Figure 1 is a diagrammatic plan of a temperature control apparatusapplied to a galvanizing pan, for carrying out the novel method of thisapplication.

Figure 2 is a side elevation of the burner regulating mechanism.

Figure 3 is a sectional elevation on the line III-1H of Figure 2.

Figure L is a top plan of the contact and depressor elements of therelay instrument.

Figure is a transverse section through the elements of Figure 1.

Referring more particularly to the drawings, the numeral 2 designates aspelter-pan containing the molten spelter through which wires 3 arecontinually passed to be coated. The spelter-pan 2 isadapted to beheated by gas or oil burners 4 adjacent the entrance end of the pan. Theburners 4 may be of any usual design and receive air from an air main 5and fuel from a fuel supply pipe 6 having branches? leading to theseparate burners. The branch pipes 7 are each provided with valves 8 tocontrol the feed, of fuel to the respective burners.

A burner control or regulating apparatus is provided for regulating thefuel and air supply to the burners. This apparatus is of standardcommercial design obtainenergized by able on the open market and,therefore, will i only be diagrammatically. illustrated and generallydescribed. ing apparatus comprisesa main drive-shaft 9 having a driveratchet-wheel 10 secured thereon at one end and having sprocketwheels11, 12 and 13 secured thereon. No teeth are formed on a portion of theperiphery of the ratchet-wheel 10, so as to limit its movement; that is,so that when this portion of the ratchet-wheel is opposite the operatingpawls, to be described, the pawls will not effect a movement of thewheel, thereby providing a limit to the burn-- er operation.

The sprocket-wheel 11 is connected by a chain 11 to a sprocket-wheel 14on a damper-s'haft 15 of a damper or valve 16 in the air main 5, so thatrotation of the shaft 9 will operate the damper or valve 16.

The sprocket-wheel 12 is connected by a chain 17 to a sprocket-wheel 18on the shaft The burner regulatof one of the valves 8, while thesprocketwheel 13 is connected by a sprocket-chain 19 to a sprocket-.wheelj20 on the other valve 8, so that rotation of the shaft 9 will alsooperate the fuel valves 8.

The ratchet-wheel 10 is adapted to be operated by pawls 29 and 30carried by a'pawlyoke 31 which is pivotally mounted on a rocking-lever32 adapted to be continually rocked by an eccentric 33 carried by aconstantly driven shaft 34. A pair of solenoids 35 and 36 aremountedonthe lever 32 below the yoke 31, and are adapted to be energizedto rock the yoke 31 so. as to engage either of the pawls 29 or 30which;..due to the con- 'tinuous rocking movement .of the lever 32,

will cause a step by step rotation of the ratchet 10 and shaft 9 as longas the solenoid remains ener 'zed.

The solenoids 35 and 36am adapted to be i an electric circuit which iscon-. trolled by a galvanometertype of relay instrument 37. Theinstrument 37 is of standard design and has a coil 38 encrgizable byWhile the contact a temperature controlled and adapted to deflect anelectric current, indicator-needle 39 to one side or the other of aneutral point in response to the rise and fall of the temperature in thespelter-pot 2.

'The'needle 39 is adapted to move in a space between a depressor-bar 40and a pair of contact plates 41 and 42 Which are separated by aninsulated gap 43. a

The depressor-bar 40 is connected to one line 44 of the solenoidenergizing circuit, plate 41 is connected by a Wire 45 to the one end ofthe solenoid coil 35, and the other end of the coil '35 is connected tothe other line 46 of the solenoid energizing circuit. The contact plate42 is connected by a Wire 47 to the one end of the solenoid coil 36, andthe'other end of the coil 36 is connected to the line 46 of the solenoidenergizing circuit.

' A solenoid coil 48 is connected to the lines 44 and. 46 and is adaptedto be energized to depress the depressor-bar 40.

The ratchet-Wheel 10 is adapted to be operated by pawls 29 and 30carried by a pawl-yoke 31 which is pivotally mounted on a rocking-lever32 adapted to be continually rocked by an eccentric 33 carried by aconstantly driven shaft 34.' A pair of solenoids 35 and 36 are mountedon the lever 32 below the yoke 31, and are adapted to be energized torock the yoke 31 so as to engage spouse to the rise and either of thepawls 29 or 30 which, due to the continuous rocking movement of' thelever 32, will cause a step by step rotation of the ratchet 10 and shaft9 as long as the solenoid. remains energized, .or until the smoothportion of the ratchet-wheel 10 is reached.

The solenoids 35 and 36 are adapted to be energized by an electriccircuit which is controlled by a galvanomet-er type of relay instrument37. The instrument 37 is of standard design and has a coil 38energizable by a temperature controlled electric current, and adapted todeflect an indicator-needle 39 to one'side or the other of a neutralpoint in reture in the spelter-pot 2.

The needle 39 is adapted to move in a space between a depressor-bar 40and a pair of contact plates 41 and-42 which are separated by aninsulated gap 43.

The depressor-bar 40 is connected to one line 44 of the solenoidenergizing circuit, While the contact plate 41 is connected by awire 45to the one end of the solenoid coil 35, and the other end of the coil 35is connected to the other line 46 of the solenoid energizing circuit.The contact plate 42 is connected by a Wire 47 to the one end of thesolenoid coil 36, and the other end of the coil 36 is connected to theline 46 of the solenoid energizing circuit.

fall of the tempera- A solenoid coil 48 is connected to the lines 44 and46 and is adapted to be energized to depress the depressor-bar 40. Thecircuit through the lines 44 and 46 is adapted to be regularly made andbroken by a timed make and break device represented by the contactor 49,so that the depressor-bar 40 willbe regularly depressed.

The operation of the mechanism above described is as follows- Assumingthat the needle 39 is in neutral position the depressor-bar 40 will beregularly depressed by the energization of the coil 48, Withoutenergizing oi afiecting the solenoids 35 or 36. However, should the coil38 be energized to move or deflect the needle to the left was to bepositioned between the depressor-bar 40 and the'plate 42, When thedepressor-bar is depressed, a circuit'will be completed from the line 44through the depressor-bar 40, needle 39, plate 42, Wire 47, solenoilcoil 36 and line 46, thus energizing solenoid coil 36 and rocking theyoke 31 so as to engage the pawl 29 With the ratchet-Wheel 10. The abovecir cuit will continue to be made as the depressor-bar is depresseduntil the needle 39 is moved to the right by a changein the energizationof t-hecoil 38 so as to move the needle 39 either to its neutralposition or to the right between the plate 41 and dc pressor-bar 40.

When the pawl 29 is engaged in the ratchet-wheel 10, the rocking of thelever 32 will cause operation of the burner regulating apparatus. 4

Now assuming that the coil 38 be reversely energized, or its value ofenergization he changed. so that the needle 39 is moved to the right andbetween the plate 41 and depressor-bar 40, when the depressor-bar40 isdepressed a circuit will be completed from the line 44 through the.depressor-bar 4U, needle 39, plate 41, Wire 45, solenoid coil 35 andline 46, thus energizing solenoid coil 35 and rocking yoke 31 so as toengage the pawl 30 with the ratchet-Wheel It). This last describedcircuit will continue to be made as the depressor-bar is'deprcssed untilthe needle 39 is moved to the left by a change in the energization ofthe coil 38 so as to move the needle 39 either to its neutral positionor to the left of its neutral position between the plate 42 anddepressor- When the pawl 30 is engaged in theratch- (t-wheel 10, therocking of the lever 32 will cause an operation of the burner regulatingapparatus in a reverse manner to that when ers and consequent desiredtemperature-may be had, and it is to this that my novel inventionpertains.

The mechanism above described is all standard mechanism in common useand well known to those versed in the art to which this inventionpertains and, therefore, will not be further illustrated or described.

The coil 38 of the galvanometer-type relay 37 is adapted to be energizedby current produced by a combination of thermo-couples 50, 51 and 52.Therefore, the position of the needle 39 varies according to the currentproduced by these thermo-couples.

The thermo-couple is positioned at the exit end of the pot 2 at whichpoint a constant temperature is desired to be maintained, thisthermo-couple has amajor effeet on the coil 38. The thermo-couples 51and 52 are located near the entrance end of the pot 2 close to theburners 4, one in the heated medium, and the other in the furnace orflue, respectively, and both of these thermo-couples have minor effectson the coil 38. v

The thermo-couple 50 has the prime effect on the coil 38 to cause theneedle 39 to move in accordance with temperature changes at the pointwhere the thermo-couple 50 is located toward 'or away from the gap 43.However, the thermo-couple 50 is always assisted by the otherthermo-couples 51 and 52. The thermo-couple 51 intercepts thetemperature changes due to the changes in the heat requirements, as forexample, change in the size or speed of travel of the wires. Thethermo-couple 52 quickly responds tochanges in. flue temperatures dueprimarily to changes in rate of heat evolution or heat supplied, andtends always to energize the coil 38 so as to quickly move the needle 39towards or away from the gap 43, depending on whether the burners havebeen turned on or ofl", resulting in raising or lowering the fluetemperature. The thermocouple; 52 is most sensitive so far as time isconcerned, but has a small total eflect.

As the load or heat requirement varies very little, the thermo-couple 51has little to do with the control or regulation. However,

it is essential to efi'ect a proper regulation of the pointer inresponse to changes in size or speed of the wires, or the addition ofcold spelter.

Mathematically the control can be illustrated as follows- Let: Ld=efiectof the thermo-couple 51. Fd=efiect of the thermo-couple 52. C d='efi'ectof the thermo-couple 50.

Assume Cd= constant.

Ldrl-Fd=constant.

Then Cd+Ld+Fd=constant (or setting of the gap 43).

which will cause the needle to move. into position to make the necessarycircuit to cause more fuel to be turned on. The increased fuel causes animmediate rise of temperature in the flue and increases the energizationfrom the thermo-couple 52 so that the drop of the thermo-couple 51 iscom-'- pensated for. The control is effected and normaterial change isnoted at the control point or thermo-couple 50. The thermo-couples 50,51 and 52 are connected by leads 56 and 56 57 and 57158 and 58 from theopposite sides of the respective thermo-couples through a junction orcold-end box 55 to a potentiometer unit 59.

The wire 56 from one side of the thermocouple 50 is connected to arheostat or resistance coil 60 and a wire 61 leads from the coil 60 tothe one end of the coil 38 of the relay 37. The other end of the coil 38is connected by a wire 62 to a movable contact adapted to engage with apotentiometer resistance coil 63. ,The wire 56 from the other side ofthe thermo-couple 50 is connected to one end of a potentiometerresistance coil 65.

The wire 57 leadingfrom one side of the thermo-couple 51 is connected tothe same end of coil 65 as the wire 56*, while the wire 57 from theopposite side of the thermo-couple 51 is connected to a movable contact66 adapted to have a movable con-1 tact with the coil 65.

The wire 58 from one side of the thermocouple 52 is connected to the oneend of the coil 63, while the other wire 58 from the opposite side isconnected to a movable contact 67 adapted to have a movable contact withthe coil 63.

A movable or adjustable contact 68 is connected to the end of the coil63 to which the wire 58 is connected and is adapted to have movable oradjustable contact with the coil 65.

The potentiometer unit 59 provides for the interconnecting of thecurrents from the thermo-couples 50, 51 and 52. so as to obtain desiredproportionate amounts of said currents and accumulating saidproportionate amounts of said currents into a single current to operatethe .relay 37.

By omitting or neglecting the resistances of lead wires and othernecessary connectors for the sake of simplicity, in order to determinethe proper design or value of potential reducers or potentiometers the01- lowing algebraic equations and their solu- 'tions are necessary- LetC=thermo-couple 50.

L== thermo-couple 51.

Ft=approximate flue temperaturecold end deducted. 1

Cd=deflection in degrees F. caused by thermo-couple 50.

P V Ld=deflection in degrees F. caused by (m= resistance of coil 38. ythermo couple 51. gs of potentlometer Fd=deflection in degrees F. causedby Fr=t0t il resistance of otentiometer ermo-coup 1e 63 P VL8=res1stance of sections of potentiom- Lp=resistance parallel to Cr inthe cire-ter 0011 65 m Parallel Quit. of thermo couple 5L Fs==res1stanceof sections of potentiom- -F;o=resistance parallel to Cr in the cireterc011 63 In parallel cuitof thermmcouple 52 Ce=cold end temperature ofthermo- Z=resistance coil 60 for ofisettin ef- P p fectsofthermo couples51am 52 All resistance is expressed 1n ohms. Ct=temperatum d i d. to 1All temperatures are expressed 1n degrees cold end deducted. Fahrenheit.Lt= approximate (load d temperature Using the above symbolsthe-equations are cold end de ucte as follows-- i Lp(Cr+Z+Fs) Lp Cr Z FsCr 4 i I Cr+Z+Fs Lp(Cr +Z+Fs) +(Lr-,Lp)(Lp+O1-+Z+Fs) Lp-l-Or+Z+Fs p OrLpLp(C1-+ Z+Fs)+(LrLp)(Lp+Cr+Z+F-s) (cleymng) C1'Lp LrLp+LrCr+LrZ+LrFs LpP (clearing) =OTLP F XLt substituting ig F I -Lr Lp+Cr+Z+- -)L 1) rCrLpFr Lr[Fr(Lp+Cr+Z) +Fp(Fr-FZ )]FrL?p (clearmg) OrFpLr Fr[Lr(Fp+C'r+Z)+Lp(Lr-Lp)] LrFp (demng) Cr Cr+Z+F s+Ls J 7 got (substituting for F8 andLs F rL 1(Cr Z) FpLr (Fr- Fp) LpFr(Lr Lp) as shown above and clearing)Total deflection=Ld+Fd-FCZ. The preceding values are approximately Relayinstrument setting or setting of in-' what have been employed incontrolling the 'sulated gap in relay=Ld+ F d Cd-i- Ce. temperature of athirty-four foot spelter I As an example with approximate values bathcontaining ap roximately sixty tons of as foows substituted in theformulae an molten spelter an used in the commercial idea 0 relativeeffects can be obtained- Cr==180, z=30, Fp=11, Fr=91, L =12,

Lr=88, Ct=800, Ft= 1225, Lt= 825, Ce= 100.

Ld= 80 degrees Fahrenheit. F(l=1'20 degrees Fahrenheit. Cd= 625 degreesFahrenheit. Ce=100 degrees Fahrenheit.

Total=d=insulated gap setting of relay 37 for obtaining temperature of900 at G, (Ct+Ce=900).

. be obtained in changing fromone operating product-ion of galvanizedwire. 7

By adjusting the various potentiometer coils, that is by adjusting themovable contacts alongthe coils so as to change their resistance values.in the several thermo-couple circuits, and by adjusting the insulatedgap 43 in the relay instrument 37 almost any desired temperature may becontrolled, and by shifting the position of the gap 43 alone, thedesired temperature setting may temperature to another as it is onlynecessary to shift gap 43 in accordance with the.

desired change of temperature.

While I have described my invention as applied to the regulation of thetemperature of a bath of molten spelter in a spelter pan, it will beunderstood that its use is in no wise limited thereto, but it may beused to regulate the temperature of many other forms of furnaces, fluidbodies and the like, wherever a constant temperature is desired.

It will be understood also, that while I have shown and described onespecific em- I bodiment of my invention, that I do not located at thepoint to be regulated, and

other of said elements being located at spaced points relativel closerto said source of heat than said rst named element, said elements beingadapted to supply varying independent electric currents 1n accordancewith temperature changes, and means for interconnecting said currents soas to obtain a desired proportionate amount ofeach of said currents, andfor accumulating said proportionate amounts of current into asinglecurrent, and means operable by said single current for varying the heatsupplied.

2. A temperature control mechanism C0111- prising the combination with asource of heat, of a plurality of temperature responsive elements, oneof said elements being located at the point to be regulated, and otherof said elements being located at spaced points from said first namedelement and adjacent the source of heat supplied and re-.

quired respectively, said elements being adapted to supply varyingindependent electric currents in accordance with temperature changes,and means for interconnecting said currents so as to obtain a desiredproportionate amount of each of said cur rents, and for accumulatingsaid proportionate amounts of current into a single current, and meansoperable by said single current for varying the heat supplied.

3. A temperature control mechanism comprising the combination with asource of heat, of a plurality of temperature responsive elements, oneof said elements. being located at the point to be regulated, a secondelement spaced from said first element and adjacent the source of heatsupplied, and a third element spaced from said first element andadjacent the point at which, heat is required, said elements beingadapted to supply varying independent electric currents in accordancewith temperature changes,

and means for interconnecting said currents so as to obtain a desiredproportionate amount of each of said currents, and for accumulating saidproportionate amounts of current into a single current, and means0perable by said single current for varying the heat supplied.

4. An electrical paratus comprising the combination with a receptaclefor containing material to be heated, and a source of heat for heatingsaid material, of a temperature responsive element located in thematerial to be heated at approximately the point at which thetemperature of the material is to be controlled, a second temperatureresponsive element located in the material closely relative to thesource of heat, and a third heat responsive element located in the pathof the heat from said source of heat so as to respond to the varyingquantities of heat evolved from said-source of heat, sald temperatureresponsive elements being adapted to supply varying independent electriccurrents in accordance changes, and meansfor interconnecting saidcurrents so as to obtain a desired proportemperature control ap- I withtemperature tionate amount of each of said currents,

and for accumulating. said proportionate amounts of current into asingle current, and means including a single galvanometer operable bysaidsingle current for varying the heat supplied.

5. An electrical temperature control apparatus comprising thecombination with a receptacle for containing material to be heated, anda source of heat for heating said material, of a thermo-couple locatedin the material to be heated at approximately the point at which thetemperature of the material is to be controlled, a second thermocouplelocated in the material to be heated closely relative to the source ofheat, anda third thermo-couple located in the path of the heat from saidsource of heat so as to respond to the varying quantities of heatevolved from said source of heat, said thermo-couples being adapted tosupply varying independent electric currents 1n accordance withtemperature changes, and means for interconnecting said currents so asto obtain a desired proportionate amount of each of said currents, andfor accumulating said proportionate amounts of current into a singlecurrent, and means including a single galvanometer operable bysaid'single current for varying the heat supplied.

6. An electrical temperature control apparatus comprising thecombination with a re ceptacle for containing material to be heated, anda source of heat for heating said material, of a thermo-couple locatedin the material to be heated at approximately the point at which thetemperature of the material is to be controlled, :1 second thermo-couplelocated in the material to be heated closely relative to the source ofheat, and a third thermo-couple located in the path of the heat fromsaid source of heat so as to respond to the varying quantities ofheatevolved from said source of heat, said thermo-couples being adaptedto supply electric currents varying in quantity in proportion to thevarying temperatures affecting the thermo-couples, a potentiometer unithaving means for interconnecting and accumulating said currents fromsaid thermo-couples, said means being adjustable. to obtain variousproportionate amounts of at least some of said currents, and meansoperable by the accumulated current for varying the source of heat.

7. In a temperature control apparatus including a plurality of sourcesof electric current and means for varying the electric currents inproportion to temperature changes, of a potentiometer unit having meansfor interconnecting and accumulating said currents, said means beingadjustable to accumulate various proportionate amounts of at least someof said currents.

8. In a temperature control apparatus including a plurality ofthermo-couples affected by the temperatures to be controlled so as toprovide electric currents varying in proportion to the temperaturechanges, of a potentiometer unit having means for interconnecting andaccumulating said currents said means being adjustable to accumulatevarious proportionate amounts of at least some of said currents.

9. In a temperature control apparatus including a plurality ofthermo-couples affected by-the temperatures to be controlled so as toprovide electric currents varying in proportion to the temperaturechanges,of a

potentiometer unit having means for inter-,

of a temperature control system comprising a movable control, aplurality of thermocouples cooperating to determine the position of saidcontrol, one of said thermo-couples being located at a point at which aredetermined constant temperature is desired and representing aconstant, and the other of said thermo-eouples being more closely ad- Ijacent' the source of heat and in the path of the heat required andsupplied res ectively, the sum of the efi'ectof said ast namedthermo-couples representing a constant, and means operated by saidcontrol to regulate said source of heat to oppositely influence saidlast mentioned thermo-couples.

11. In a temperature control system, a

galvanometer, a plurality of thermo-couple circuits cooperating todetermine the position of said galvanometer, one of said thermo-couplecircuits representing a constant, and the sum of the other circuitsrepresenting a constant, and a fuel control operated by saidgalvanometer to oppositely influence said last mentioned circuits.

In testimony whereof, I have hereunto signed my name. 1

ALBERT BONDS.

